Fruit and vegetables and cancer prevention

Tuesday 28 August, 2007

Recent media reports have stated that fruit and vegetables give little protection against cancer.

The Cancer Council Victoria's position on this issue is as follows.

  • The reports are in reference to the Melbourne Collaborative Cohort Study, which has not found that fruit and vegetables offer significant protection against cancer. However, there is some evidence from international studies (mostly case-control studies) that fruit and vegetables are, in fact, beneficial.
  • It is important that people don't see the recent media coverage as an excuse not to eat fruit and vegetables.
  • Fruit and vegetables are high in nutrients that are potentially protective against cancer. They also play an important role in weight management. As obesity is a known risk factor for cancer of the colon, breast (in post-menopausal women), endometrium, kidney and oesophagus, fruit and vegetables may also protect against cancer indirectly by helping to maintain a healthy body weight.
  • The International Agency for Research on Cancer (IARC) concluded that 5-12% of cancers could be attributed to low fruit and vegetable consumption.

Although there has been a slight weakening of the evidence supporting the role of fruit and vegetables in reducing the risk of some cancers, overall the evidence is suggestive of a protective effect. Recent studies show that fruit and vegetables are protective against oral, laryngeal, oesophageal, colorectal and lung cancers.

  • Fruit and vegetables are important components of a healthy diet and cancer smart diet, because they are low in kilojoules and high in nutrients (such as fibre, vitamins and antioxidants).

Fruit and vegetables also contain natural protective substances, such as antioxidants, that can destroy cancer-causing agents (carcinogens).

  • To reduce the risk of certain cancers, the Cancer Council recommends a healthy body weight, regular exercise and a healthy diet.
  • The Cancer Council supports the Australian Dietary Guidelines that recommend eating plenty of fruit and vegetables, and the population recommendation of at least two serves of fruit and five serves of vegetables daily.

Why exactly is it that food can have a big impact on the development and delay of the disease?

This is not an easy question to answer as this is still an active area for research. Some foods are thought to increase risk and some are thought to reduce the risk of cancer. The foods that are thought to increase risk work in two ways: first by containing substances that might damage DNA and second by containing substances that encourage cancer cells to grow. The foods that are thought to protect against cancer do the opposite; they protect DNA from damage and they inhibit cancer cells from growing.

Media contact: Emma Fay, 0415 477 537